HVAC / Home-Services Acquisition & SBA Underwriting Financial Model — Maintenance Book, SBA 7(a), DSCR (Excel + Google Sheets)

You’re not just buying trucks and a customer list. You’re buying the maintenance book. This model underwrites an HVAC / home-services acquisition the way your SBA lender actually will — so you know whether the deal is financeable before you sign the LOI.

It’s a 10-sheet Excel workbook (fully Google Sheets-compatible — no macros, no add-ins) built for a self-funded searcher or buyer using an SBA 7(a) loan to acquire a residential or light-commercial HVAC company. Every formula is machine-verified by three independent engines.

What makes it different — the Maintenance-Agreement Recurring-Revenue Engine:

• The recurring book as the value driver. Revenue is built bottom-up: the maintenance-agreement book (active agreements × annual ARPU) with attach and renewal rates, plus service/repair (calls × ticket) and install/replacement (jobs × price). The sticky, renewable book is broken out as the line that justifies the multiple — and the line a lender leans on.
• Revenue-mix → SDE, bottom-up. Each line carries its own gross margin, so Gross Profit and therefore SDE are operating outputs, not a guessed blended number. Two HVAC shops with the same revenue but a different mix earn — and are worth — very different amounts, and the model shows exactly why. SDE margin is held realistic (~16%), not an inflated 25%+.
• Technician-capacity check. Revenue per technician and an implied billable rate sanity-test whether the revenue the book implies is physically deliverable.
• The seller-note standby lever. One toggle — full standby or amortizing. Full standby pays no cash, counts toward your 10% injection, and keeps the deal bankable at 1.31x DSCR; flip it to amortizing and coverage drops below the 1.25x floor. This switch is often the difference between financeable and declined.
• The lender’s DSCR gate — with maintenance-book coverage. DSCR = (Adjusted EBITDA − maintenance capex) ÷ total cash debt service, computed on the cash flow a bank accepts, after a market operator salary. The HVAC-specific headline: the recurring book’s gross profit alone covers ~111% of annual debt service — the sticky revenue nearly services the acquisition debt by itself. Plus a debt-yield cross-check.
• 3 HVAC profiles in one file. A toggle reloads the per-line margins, the entry/exit multiple, the working-capital peg and maintenance capex for Residential Service & Replacement, Replacement & New-Construction, or a Light-Commercial Mix.

What you get: the 10-sheet workbook, a 20-page PDF user guide (quick start, sheet-by-sheet walkthrough, how the maintenance-book engine and the revenue-mix SDE build work, how the capital stack and DSCR gate work, the standby lever, and a full FAQ), a DSCR sensitivity grid across multiple × rate, and a benchmarks sheet with sourced 2025-26 HVAC multiples, margins, agreement economics and SBA terms.

Honest by design. SDE margin is a realistic 16%, not an inflated number a lender’s quality-of-earnings would haircut. Returns are leverage-amplified — a ~10% equity check on a ~90%-financed deal — and the model says so rather than dressing it up. The private-equity platform’s multiple arbitrage (buy at 4x, sell the aggregate at 7-12x) is NOT a single-shop buyer’s return, and the model does not pretend it is. We deliberately do not headline an IRR: on a single small deal it is hostage to the exit multiple you assume. The robust numbers — DSCR, maintenance-book coverage, debt yield, cash-on-cash and the equity multiple — are front and centre.

Educational planning tool — not financial, investment, tax, lending or legal advice. SBA rules, rates, HVAC multiples and margins vary by lender and change over time; SDE and add-backs must be documented and accepted by your lender’s quality-of-earnings. Billable hours per technician and van replacement life are estimates. Verify the seller’s agreement book, tax returns, your SBA term sheet and a quality-of-earnings before relying on any number.